Jump to content
SAU Community

RB25 Starting Issues, Possible The CAS

tylink720
 Share

Recommended Posts

tylink720 Explorer

tylink720

Posted
Posted

Hey,

I'm having some starting issues with my rb25det neo. Its in a pretty much stock R34 GTT with an Elite 2000. It will just crank and not start, but sometimes will fire right up. I'm wondering if its my CAS that is the issue, but once it does start, it seems to run great.

It started this year after the Haltech install. Never had an issue before, and it worked perfectly for a week after installing the haltech too. The first time it happened, I could smell unburnt fuel, so I pulled the fuel pump fuse and it started up, so I thought it was just flooded. Now that doesn't work. 

I put the timing light on it again, and the crank timing marks were nowhere to be found. Took the cas off thinking the key snapped, but it was fine. Put it back on and it started, and I checked the timing again and it was lined back up. Its almost like the ecu was seeing the timing 180 degrees out somehow. This has happened multiple times now, including this morning.

Some things I've tried:

  • I've taken out each coilpack and I get spark from all of them while turning my cas, and I hear the injectors clicking too.
  • I've synched my timing with the ecu each time.
  • I've cleaned the cas with sensor cleaner.
  • I've logged the ecu while cranking and it's getting signal from the cas.
  • I've looked over some wiring and can't see frays or anything. 
  • Double checked my trigger settings, and they are the same as the original base map

I'm nervous to drive around now as it seems to be random when it wants to start. And it seems strange that once it actually starts, it runs great. Any ideas? I don't know anyone with a confirmed working cas otherwise I'd try swapping to see it it helped. 
 

robbo_rb180 Grand Master

robbo_rb180

Posted
Posted

What is the condition of your battery as voltage may be dropping below arming/trigger setting. Adjust them if need be.

Check that and if not the problem invest in a NZwiring trigger kit. Super easy to install and setup too.
https://www.nzwiring.com/index.php/product/trigger-kit/

  • Like 2
tylink720 Explorer

tylink720

Posted
  • Author
Posted

Hey thanks for the reply. Yep I've been looking at some trigger kits so I might just have to take the plunge and buy one.

The battery seems to be good, and I've also tried starting while being jumped by another running car, with no luck. I will see if I can find the those voltage settings in the ECU and give it a go.

tylink720 Explorer

tylink720

Posted
  • Author
Posted

Update on this:

I got the car sketchily started and made it home now. I had to add 40 degrees to the TDC Angle setting in the Haltech and then it barely started but idled like crap. Put the timing light on it and sure enough the timing was out by about the 40 degrees. I put the same number I had before back in, 115, and its back to proper timing and idled fine.  

Somethings off when its cranking it seems. I'm planning on just buying the trigger kit now

joshuaho96 Veteran

joshuaho96

Posted
Posted
On 6/21/2022 at 9:09 AM, tylink720 said:

Update on this:

I got the car sketchily started and made it home now. I had to add 40 degrees to the TDC Angle setting in the Haltech and then it barely started but idled like crap. Put the timing light on it and sure enough the timing was out by about the 40 degrees. I put the same number I had before back in, 115, and its back to proper timing and idled fine.  

Somethings off when its cranking it seems. I'm planning on just buying the trigger kit now

Scope the signal the ECU sees during cranking. This sounds like it could be a signal integrity issue.

tylink720 Explorer

tylink720

Posted
  • Author
Posted
On 6/21/2022 at 4:44 PM, joshuaho96 said:

Scope the signal the ECU sees during cranking. This sounds like it could be a signal integrity issue.

I will try this as well thanks. I've ordered up the NZ Wiring kit so hopefully that will be here soon too

  • Like 1
  • 2 weeks later...
tylink720 Explorer

tylink720

Posted
  • Author
Posted

Another update for this. I put the NZ Wiring trigger kit on and it was doing the same thing. Scoped the signals and was getting perfect readings off of it. 

Ended up going through all of my fuses again and found one had blown, one of these ENG CONT fuses.image.thumb.png.3115d0907a47a0d115022a1c07edca46.png

Replaced it and the last 3 starts have been flawless. I'm hoping that this is finally the fix for it!

Side note, what do these 2 fuses actually do? I'm wondering how the car was even able to run if it was blown?


 

Duncan Grand Master

Duncan

Posted
Posted

Yes, but the weird thing is, a standard 33 gtst runs fine with that fuse blown, while at least some aftermarket ECUs need it (it was actually absent from factory in S2 which is even weirder.) I've never traced the wiring for it though

  • Like 1
  • 3 weeks later...
tylink720 Explorer

tylink720

Posted
  • Author
Posted (edited)

The starting issue seems to be fixed due to replacing that fuse. I also emailed NZ Wiring and he gave me some tips and I have the car working very well now. Had to lower my trigger arming voltages a lot compared to the numbers in the install instructions. Thanks for the help!

I do get a trigger error once every couple of drives. It seems to happen when I press in the clutch during a lower rpm decel, or when letting out the clutch at a low rpms. It will happen once, then wont come up again for the rest of the drive or even multiple drives after. Strange

Edited by tylink720

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • cobo_11
      My BMW 335i

      By cobo_11 · Posted

      Noted. Have noticed BMW are more 'high maintenance' for sure. They've attracted my attention as I think the used car prices seem reasonable vs other options, and the extra quality overall vs a commodore / camry / corolla or similar of the same vintage is appealing, especially the interior, and they are more on the sporty side whereas the others mentioned can be more cruising or economical A-to-B only.
    • cobo_11
      My BMW 335i

      By cobo_11 · Posted

      Haha yeah I know, this is SAU after all, why are we talking about BMW's of all things!? I hear you on the 'don't have to worry about it' side of things. Having been fortunate enough to be have been able to buy a brand new motorbike or two...never really enjoyed them as much as I'd have liked as you worry so much about where you park it, will it get scratched, stolen, attempted theft, knocked over, etc...and yes dirty. Older less valuable bikes you can just go where you want and park it wherever and not really worry that much in comparison. And who cares if it gets dirty! Never owned a V8, and have had my eyes on VE / VF commodores for years but with their prices climbing so high, the M3 has come into focus more as prices are much closer than I've ever seen...is it a potential contender now?...of course need to factor in the S65 'maintenance' especially and like you said general M car 'tax'. One can dream anyway. But more on the reality front - did read the whole 330i thread as well and was a great read too, both threads enlightening as I've never even driven one of these cars! I do recall 330i didn't seem to have the same amount of issues for almost the same car (turbos and related differences notwithstanding)...perhaps down to getting it earlier in it's life so looked after better than the 335i? Perhaps so as your 130i has been good and quite similar, so finding a car that's been looked after well is the especially-crucial-BMW-first-step.
    • luke gtr
      So i brought a boat...

      By luke gtr · Posted

      Nice. Dont worry about the time of not running. My current skyline hasn't run since I bought it. About 8 years ago.
    • PranK
      My BMW 335i

      By PranK · Posted

      It's also worth noting that I am heavily and unconditionally biased. I've had a lot of cars including some GTRs a fair while ago. I love my BMW's now a lot. They make no sense a lot of the time and the guys on here remind me regularly that I could get something else that does what I want better and cheaper. If you're going to take on an older BMW it's definitely a commitment. If you bail on it early you'll lose money and also the ability for it to put a smile on your face. Stick with it and it just gets better.  f**k I should get into advertising.  
    • PranK
      My BMW 335i

      By PranK · Posted

      Careful with posts like that around here without the flame suit on @cobo_11! 😂😂 My 330i journal is on here too. That car was so good and super reliable. We still have a 130i in the family which is almost identical to the 330i and easier to find in manual. It has also been almost faultless over the 6 or so years in the family.  I used to want an M car a lot more than I do now but if I'm honest and without trying to sound like a wanker, I can get such good performance and handling out of my 335 without needing to worry about all the crap that goes along with M car ownership. I don't need to worry about my bearings or subframe issues or the cost of replacing brakes or suspension or whether it has been impeccably maintained. And I can leave it places and not get upset when it's always filthy.
×
×
  • Create New...